In this issue

Abstract

Wewould like to draw your attention on several interesting and clinically relevant articles which you will find in this issue. A systematic review by Lu et al. (https://doi.org/10.1007/ s00428-020-03009-x) analyzes standardized reporting of discontinuous tumor involvement (DTI) in prostate core needle biopsies. DTI is a frequent finding in prostate biopsies and may result rather from under sampling of irregular tumor areas than from multifocality. Linear measurement of DTI which includes the intervening prostate stroma seems to be predictive of the pathologic findings after radical prostatectomy and also a prognostic factor. Cancer immunotherapy may also be an option for the management of advanced squamous cell carcinoma (SCC) of the uterine cervix. D’Alessandris et al. (https://doi.org/10.1007/ s00428-020-02922-5) investigated the role of stromal TILs and PD-L1 expression in cervical SCC and found both the presence and PD-L1 positivity of stromal TILs associatedwith good response to neoadjuvant chemotherapy. The PD1/PD-L1 pathway also seems to play an important role in the pathogenesis of Epstein-Barr virus–positive diffuse large B-cell lymphoma, not otherwise specified (EBV+ DLBCL, NOS), which was studied by Takahara et al. (https://doi.org/10.1007/s00428-020-02901-w). The authors found in an elderly collective of patients PD-L1 expression only in a small subset of cases which is in contrast to reports from younger age groups. In addition, these patients with PDL1 positive, EBV+ DLBCL, NOS showed poor outcome. Pehlivanoglu et al. (https://doi.org/10.1007/s00428-02002877-7) tried to better characterize preinvasive tumorforming neoplasms of the gallbladder. These tumors (as illustrated on the cover page) which cytologically qualify as high grade tend to occur in uninjured gallbladders and in association with cholesterol polyps. Since they do not seem to show invasive growth, they seem to warrant a separate classification from high grade dysplasia/carcinoma. Lohneis et al. (https://doi.org/10.1007/s00428-020-028973) studied tumor budding in esophageal adenocarcinomas according to the criteria of the International Tumor Budding Consensus Conference (ITBCC). They found that tumor budding is prognostically significant if the ITBCC criteria are followed. Yanai et al. (https://doi.org/10.1007/s00428-020-02906-5) studied appendiceal mucinous neoplasms by next generation and Sanger sequencing and found RNF43 mutations in a subset of cases. RNF43 mutations were almost exclusively associated with RAS mutations, occurred at a later stage of mucinous adenocarcinoma development and were not associated with pseudomyxoma peritonei. Zhao et al. (https://doi.org/10.1007/s00428-020-02925-2) found that MFAP5 expression is down-regulated in the desmoplastic stroma of gallbladder adenocarcinoma, which may be diagnostically useful in difficult cases. Sakuratani et al. (https://doi.org/10.1007/s00428-02002899-1) studied ARID1A expression in gastric carcinoma and found that low ARID1A expression is associated with poor prognosis. The low ARID1A expression also concurred with low expression of the mitochondrial apoptosis mediator Harakiri which may represent a potential pathogenetic pathway. Predictive biomarker testing is crucial for the choice of therapy in modern oncology and personalized medicine and, therefore, relates on high quality. Dufraing et al. (https://doi. org/10.1007/s00428-020-02928-z) report on an initiative to revise and harmonize external quality assurance by several providers based on current evidence-based knowledge, developed recommendations and the experience from the last years. Digital pathology using whole slide imaging has a potential to make expert consultation and expert panel diagnosis more rapid and more efficient but requires comparison with current methods for validation of the technique. A study on lymphoma cases by van den Brand et al. (https://doi.org/10.1007/ s00428-020-02907-4) found discrepancies between different investigators more frequently for digital microscopy although the level of confidence and the need for additional investigations was similar between the two techniques. Tsuda et al. (https://doi.org/10.1007/s00428-020-02914-5) frequently found nuclear expression of mdm2 in hibernoma irrespective of the content of brown adipose tissue. In contrast, https://doi.org/10.1007/s00428-021-03058-w